Leaf spring switching means

ABSTRACT

A switch having a plurality of leaf spring type contacts held in a stacked, but spaced-apart manner, with each spring having one end thereof secured in a common plastic base. The base has slots formed therein to receive the leaf springs and also has holes therein, at right angles to the plane of the slots, to receive lead-in wires. To assemble the switch, the lead-in wires are simply cut off at their ends and inserted into their respective holes. The leaf springs are then inserted in their respective slots. Each leaf spring has a slotted appendage thereon which slips over a particular and unique lead-in wire within the housing, cuts away the insulation thereon, and makes contact with the metal conductor therein. The assembled switch requires no discrete terminals secured to the ends of the lead-in wires nor any screws, bolts or other fastening means to hold the leaf springs in the common base. The plastic housing holds the leaf springs therein by force-fit means.

United States Patent [1 1 Townsend LEAF SPRING SWITCHING MEANS [75]Inventor: Peter Keith Townsend, Cumberland,

[73] Assignee: AMP Incorporated, Harrisburg, Pa. [22] Filed: Nov. 5,1973 [21] Appl. No.: 413,078

Primary Examiner-Harold Broome Attorney, Agent, or Firm-AMP incorporatedMay 6,1975

[ 57] ABSTRACT A switch having a plurality of leaf spring type contactsheld in a stacked, but spaced-apart manner, with each spring having oneend thereof secured in a common plastic base. The base has slots formedtherein to receive the leaf springs and also has holes therein, at rightangles to the plane of the slots, to receive lead-in wires. To assemblethe switch, the lead-in wires are simply cut off at their ends andinserted into their respective holes. The leaf springs are then insertedin their respective slots. Each leaf spring has a slotted appendagethereon which slips over a particular and unique lead-in wire within thehousing, cuts away the insulation thereon, and makes contact with themetal conductor therein. The assembled switch requires no discreteterminals secured to the ends of the lead-in wires nor any screws, boltsor other fastening means to hold the leaf springs in the common base.The plastic housing holds the leaf springs therein by force-fit means.

16 Claims, 29 Drawing Figures PATENTEDHAY 6 I975 SHEET UlUF 5PATENTEDHAY 51975 sum near 5 PATENIEU w 'sizs SHEET 03 UP 5 SECTION B-E;

PATENTEDHAY 61975 3.882.296

' SHEET w ssJ 7225/ 72E]; /215 7171-, L? 71-22737? 71E H 71-2: M;

Th Z5 [5 71.7 15 71-, .15; E, 12 T5125 LEAF SPRING SWITCHING MEANSBACKGROUND OF THE INVENTION This invention relates generally toswitches, and more particularly to switches of the type known as lineswitches which are employed extensively in the telephone industry, butwhich have many other applications, as well.

Essentially, a line link switch is a series of leaf spring type contactswhich are stacked, one over the other, and secured in such stackedposition by a plurality of insulated spacers positioned at one end ofthe leaf springs and in-between adjacent leaf springs. A pair of screwsextend through the stack of spacers and leaf springs to hold them inposition. The free end of each of the leaf springs has at least onecontact formed thereon and in bifurcated in nature so that what is knownas a card can be inserted into the slots formed by such bifurcations. Asthe card is moved to and fro, in a line perpendicular to the plane ofthe leaf springs, electrical contacts between various adjacent ones ofthe spring leaf are made or broken to perform desired electricalswitching functions.

At least one of these leaf springs is employed in each telephone handset. Furthermore, large quantities of these type switches are employedin other switching equipment in the telephone industry. Also extensiveuse of this type switch is made in many other kinds of electricalequipment, such as for example, pin ball machines, appliances andindustrial controls.

In the presently employed line link switch, bolts or screws extendthrough the alternate stack of leaf springs and insulating spacers orseparators positioned therebetween, to hold the entire assembly of leafsprings together in a desired relationship. An external electricalconnection is made to individual ones of the leaf springs by means of aspade-like termination secured to lead-in wires. These spade-liketerminations are positioned between the leaf spring to which it isconnected and an adjacent insulating spacer. The screws that hold thespacer or separator and leaf springs together also function to hold thespade terminal in its place and in electrical contact with one of theleaf springs.

The cost of the presently employed line link switch is fairly high forseveral reasons. More specifically, each of the lead-in wires has aspade-like termination thereon, as mentioned above, in order to connectwith one of the spring leaf contacts. Furthermore, a plurality ofinsulating spacers must be manufactured and then individually positionedin-between the various spring leaves. Each of the spring leaves andinsulating separators must have a pair of holes drilled therein toreceive the two screws which hold the entire assembly together. It isalso apparent that in the manufacturing thereof, means must be providedto stack the leaf springs and the separators together in the properorder and with the holes therein aligned so that the supporting screwscan be inserted.

BRIEF STATEMENT OF THE INVENTION It is a primary object of the presentinvention to provide a line link switch of at least equal quality andreliability to the presently used line link switch, but having afraction of the manufacturing cost thereof.

It is a second aim of the invention to provide a line link switch whichdoes not require separate insulating spacers.

It is a third aim of the invention to provide a line link switch whichdoes not require separate insulating spacers nor does it require spadeor other type discrete terminals connected to the lead-in wires.

It is a fourth purpose of the invention to provide a line link switchwhich does not require separate insulating spacers, nor discreteterminals for making contact between the lead-in wires and the springcontacts nor does it require any screws or bolts to hold the leafsprings and spacers to together as an assembly.

It is a fifth purpose of the invention to provide a line link switchhaving a connector housing into which the cut end of the insulatedlead-in wires can be inserted and into which each of the leaf springssubsequently can be inserted thereby stripping away the insulation onselected lead-in wires to thereby make a good and permanent electricalconnection with said lead-in wires.

It is a sixth purpose of the invention to provide a line link switchcomprised only of leaf springs, a plastic housing and a metal bracket,and in which cut ends of lead-in wires are inserted into the plasticbase followed by insertion of the leaf springs, each of which functionsto strip away the insulation on a given one of the lead-in wires to makeelectrical connection therewith, and further in which said plastichousing and the leaf springs co-act together so that insertion of theleaf springs into said housing provides the structural strength tosupport said leaf springs without the aid of any additional support.

It is a further object of the invention to provide a line link switchconsisting only of a plastic housing, a plurality of leaf springs, aplurality of lead-in wires and a metal bracket, and in which allelectrical connections and all required mechanical support is obtainedby simply inserting the leaf springs into slots provided therefore insaid plastic housing.

Another aim of the invention is the improvement of line link switchesgenerally.

In accordance with the present invention there is provided a plastichousing having a plurality of slots, usually seven, which aresubstantially parallel to each other and with the openings thereof allon one major, flat surface of the housing. A plurality of holes, alsousually seven, are formed in said housing substantially at right anglesto the plane of the slots and with the holes penetrating into thehousing to different depths, and more specifically with each holeextending just beyond one of the given slots so that when theleaf-spring is inserted in said one slot said leaf spring will engageonly the lead-in wire inserted in said each hole. The seven holes can bearranged into two rows of holes, one on either side of the stack ofslots and with the holes aligned at substantially right angles to themajor planes of the slots. The holes nearest the slot openings in eachrow penetrate past only the first slot, the next hole penetrating justpast the second hole, etc. With the foregoing arrangement each leafspring, when inserted in its slot, will engage only one lead in wire.

The engagement between the leaf springs and the lead-in wires iseffected by means of an appendage which extends out from the side ofeach leaf spring and which contains a slot. When said leaf spring isinserted into the housing slot, the slot in the appendage slides overthe lead-in wire inserted in the hole associated therewith and stripsthe insulation from said lead-in wire, thereby making electrical contactbetween the spring leaf and the lead-in wire.

Spring-like finger elements and embossed areas are formed on each of theleaf springs which function to grip the walls of the slot into which theleaf spring is inserted so as to provide a rigid support in said housingfor the spring leaf, and further to prevent unauthorized extraction of aspring leaf from the plastic housing. Each of the seven spring leavescan be inserted separately, or simultaneously by an appropriate tool orantomated equipment. To assemble the switch it is only necessary toinsert the lead-in wires into their proper holes in the housing followedby insertion of the leaf springs into their proper slots. A metalbracket is provided to hold the assembled switch onto a suitable chassiswhich is provided therefor, as for example, in telephone bases.

In accordance with a feature of the invention the slots formed in theappendages on the spring leaves have their edges bent at right angles tothe plane of the leaf spring so that the slot formed thereby is largestnear the open end thereof and decreases in width towards the top orclosed end thereof. Thus, as said slot is pressed down over the lead-inwire there are no sharp edges which will cut through the insulation andinto the copper conductor contained therein to damage said conductor.The action of said slot with its bent-over edges is, in effect, to wearaway the insulation on the wire as the slot is pressed down and oversaid wire, thereby providinga safe means of removing the insulation fromthe lead-in wire but yet establishing good electrical contact with themetal conductor as the slot finally seats upon said conductor.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other objectsand features of the invention will be more clearly understood from thefollowing detailed description thereof when read in conjunction with thedrawings in which:

FIGS. 1 through 4 show four perspective views of the switch in variousstages of assembly;

FIG. 5 shows a broken away perspective view of one leaf spring insertedinto the plastic housing and the physical connection it makes with alead-in conductor inserted in the hole therefore in said plastichousing;

FIG. 5a is a perspective view of one leaf spring;

' FIG. 5b is a blown-up view of a portion of the structure of FIG. 5a;

FIG. 6 is a top plan view of the plastic housing showing the openings ofthe slots provided for the spring leaves;

FIG. 7 is a sectioned view taken along the plane CC of FIG. 6;

FIG. 8 is a sectioned view taken along the plane BB of FIG. 6 and showsthe intersection of three of the slots and the holes for the lead-inwires on one side of the stack of slots;

FIG. 9 is another sectional view of FIG. 6 taken along the plane A-A andshows the intersection of four of the slots for the spring leaves andthe holes provided for the lead-in wires;

FIG. 10 is an end view of the structure of FIG. 6 and shows theentrancesof the seven holes provided for the seven lead-in wires;

4 FIGS. 11, 110,12, 12a, 13,13a,14,l4a,l5,15a,16,

16a, 17, and 17a show plan views and side views of each of the sevenspring leaf elements;

FIGS. 18 and 19 show the switch in its two operating positions; and

FIG. 20 shows a perspective view of the card element 100 employed in theswitch.

DETAILED DESCRIPTION OF THE INVENTION The invention will be most readilyunderstood from a consideration of FIGS. 1 through 4 in conjunction withFIGS. 5 through 8. More specifically FIGS. 1 through 4 showthe lineswitch in various stages of assembly. The invention will be described bydiscussing the insertion of one of the lead-in wires 34 into the housing20 followed by the insertion of the leaf spring 21 into the housing 20,as shown in FIG. 1. With the aid of FIGS. 6 through 9 it will be shownhow the leaf spring 21 interacts with the lead-in wire 34 within thehousing to make an electrical connection with said lead-in wire 34, andalso to provide a good mechanical support in the housing for leaf spring21.

Next, the insertion of a second wire 30 and the insertion of a secondleaf spring 22 into the housing 20 will be discussed, as shown in FIGS.1 and 2. Again the coaction between the second leaf spring 22 and thewire 30 will be explained with the aid of FIGS. 6 through 9.

From the discussion of the assembly of the two wires 34 and 30 and theleaf springs 21 and 22 it will be apparent how the remaining fivelead-in wires 35, 36, 31, 32 and 33, and the remaining five leaf springs23, 24, 25, 26 and 27 are inserted into the housing 20 to complete theassembly of the switch.

The details of the construction of the seven different leaf springs andthe means by which they are activated, one with respect to another, willthen be discussed in connection with FIGS. 18 and 19.

The different configurations employed in each of the seven leaf springsare shown in FIGS. 11 through 17 and will be discussed with respect tosuch Figures.

Referring now specifically to FIG. 1 a lead-in wire 34 is shown as beinginserted in aperture 34a and the leaf spring 21 as being inserted inslot 21a. In their inserted positions the insulation on the wire 34a isworn through by a slot-containing projection on leaf spring 21. Theintersection of the slot 21a with the aperture 34a can be seen in FIG.8, which is a sectional view taken along the plane BB of FIG. 6.

The condition that exists when leaf spring 21 is inserted in slot 21aand wire 34 is inserted in hole 34a is shown in the broken-awayperspective view of FIG. 5. The actual connection between leaf spring 21and wire 34 occurs as a result of a tab or projection 71 which isattached to leaf spring 21. Such tab 71 has a slot formed therein, withthe opening of the slot 70 being at the bottom of tab 71. Thus, whenleaf spring 21 is inserted downwardly in slot 21a in the direction ofarrow 72, the slot 70 in tab 71 will pass over wire 34 and, in effect,squeeze away the insulation on said wire 34 and make electricalconnection with the metal conductor 73 contained therein.

The leaf spring 21 is shown in more detail in FIG. 5 and in theperspective view in FIG. 5a wherein the details of the slot 70 and thetab 71 can be seen more clearly. More specifically in FIG. 5a it can beseen that slot 70 has the sides 73 and 74 thereof bent over intotriangularly shaped sections at to the plane of the tab 71.- Further,slot- 70 is wider at the bottom than it is at the top portion 75thereof. Thus when tab 71 is moved down upon conductor 34 the innersurfaces of the triangular elements 73 and 74 will function to literallywear away the insulation on the lead wire 34 and by the time the wire 34reaches the top of the slot 75 the insulation will have been worn awayand electrical contact will be made between the sides of the slot andthe wire 34.

It is to be noted that the wearing away of the insulation on wire 34rather than leaving sharp edges on the inside of slot 70 to cut throughthe insulation on wire 34 is desirable since the wire 78 is a fine wireof approximately wire size 27, which could be damaged by a sharp edge onthe inner surfaces of slot 70.

Due to the presence of the triangular elements 73 and 74 at the edges ofslot 70 it is necessary to widen the slot 20 in the housing 20 (see FIG.6) to permit entry of said tabs 73 and 74 therein. More specifically,the widened portion 80 of slot 20 of FIG. 6 is positioned to permitentry therein of tab 70 of FIG. 5a, and the elements 73 and 74 of tab 71of FIG. 5b.

The tabs 76 and 77, formed in the leaf spring 21, abut against the topsurface 79 of base 20, thereby determining the depth of penetration ofthe leaf spring 21 into the housing 20.

Returning again to FIG. 1, the leaf spring element 22 is the nextelement to be inserted in the housing 20. Specifically, the leaf springelement 22 is inserted in slot 22a and makes connection with the wire30, also inserted in the housing 20. The connection between lead-in wire30 and leaf spring 22 is effected by means of the slot 88 in the tab 37of leaf spring 22, as shown in FIG. 13. It is to be noted that lead-inwire 30 is inserted in a hole in the housing 20 on the opposite sidethereof from hole 34.

Reference is made to FIG. 9 which shows a sectional view of thestructure of FIG. 6 along the plane AA. It can be seen from FIG. 9 thatfour of the seven lead-in wires are inserted in the four apertures 30a,31a, 32a and 33a, which are intersected respectively by the slots 22a,24a, 26a and 27a respectively, as shown in FIGS. 8 and 9. The particularleaf spring which fits into slot 22a is shown in detail in FIG. 12. Thetab 37 on leaf spring 22 of FIG. 12 has a slot 88 therein which isformed in the same manner as the slot 70 of FIG. 5b. The sides of slot88 are formed into triangular elements bent therefrom at right angles tothe plane of tab 37, also in the same manner as the triangular elements73 and 74 of slot 70 in FIG. 5b are formed.

When spring leaf 22 is inserted in slot 220 of FIG. 1 the slot 88 in tab37 thereof will strip away the insulation on lead-in wire 30 and makeelectrical contact therewith. Such interaction between the spring leaf22 and the lead-in wire 30 can be seen from the sectional plan view ofFIG. 9 wherein it is shown that slot 22a, into which spring leaf 22 isinserted, intercepts aperture 30a, into which lead-in wire 30 isinserted.

As in the case described above hereinbefore in which the first springleaf 21 was inserted in slot 21a to intercept lead-in wire 34. Theaperture 30a extends beyond the slot 22a in FIG. 9. The lead-in wire 30will accordingly also extend beyond said slot 22a so as to bridge saidslot and provide structural strength. Thus when tab 37 of spring leaf 22is forced down over the wire 30, that portion of wire which will bestripped of insulation will be supported on either side thereof tofacilitate such stripping of the insulation therefrom.

In FIG. 2 the spring leaf 22 is shown as inserted in the base 20 alongwith leaf spring 21. In addition, the leadin wires 30, 31, 34 and 35 arealso shown as being inserted. The leaf spring 24 is shown along side thebase 20 in a non-inserted position. When inserted into base 20 thespring leaf 24 will intercept the lead-in wire 31.

In FIG. 3 five of the seven leaf springs 21, 22, 23, 24 and 25 are showninserted in base 20. Six of the lead-in wires 30, 31, 32, 33, 34, 35 and36 are also shown as being inserted in base 20. The completed assembly,including the inserted seven leaf springs 21 through 27 and the insertedseven lead-in wires 30 through 36, is

shown in FIG. 4. Also shown in FIG. 4 is a bracket. In the completedassembly the following connections between the various leaf springs andthe lead-in wires are made; leaf springs 22, 24, 26 and 27 areconnected, respectively, to lead-in wires 30, 31, 32 and 33. Springleaves 21, 23 and 25 are connected, respectively, to lead-in wires 34,35 and 36. I

Each of the seven individual leaf springs 21 through 27 have differentconfigurations and front plan views thereof are individually shown inFIGS. 11 through 17 respectively. FIGS. 11a through 17a show a side viewof leaf springs 21 through 27, respectively. From FIGS. 12 through 17 itcan be seen that each of the leaf springs 21 through 27 has a differentstamped out configuration at the bifurcated end thereof. Suchdifferences in the stamped out portion at the bifurcated ends of theleaf springs is needed in order to accommodate a card element which fitsinto the slots formed by such bifurcations and moves certain of the leafsprings back and forth to make and break contacts with other leafsprings. Reference is made to FIGS. 18 and 19 which show the seven leafsprings 21 through 27 mounted in their plastic base 20 which in turn ismounted on a metal bracket 106. The card element 100 slides down intothe slot at the bifurcated end of the leaf springs 21 through 27 and hastwo positions, one as shown in FIG. 18 and the other as shown in FIG.19, which shows card element 100 moved to the right in the direction ofthe arrow 108. Furthermore, card 100 has elements 101, 102 and 103formed thereon which are wider than the main body of card 100 andfunction to grip the bifurcated elements of leaf springs 26, 24 and 21,respectively. Thus, when card 100 is moved to its rightmost position asshown in FIG. 19, the elements 101, 102 and 103 function to pull backthe leaf springs 26, 24 and 21.

When leaf springs 26 and 24 are pulled back as I shown in FIG. 19, thecontacts 111 and 117 thereof break with contacts and 116 of leaf springs27 and 22 respectively, and the contact 114 of leaf spring 24 mates withcontact of leaf spring 23. Also, contact 112 of leaf spring 26 mateswith the contact 113 of leaf spring 25.

The circuit connections made or disconnected by the foregoing breakingand making of the contacts of the leaf springs 21 through 27 is notimportant for the purposes of this invention. The importantconsideration is that the afore-mentioned breaking and making ofcontacts is effected when the card 100 is moved from its leftmostposition of FIG. 18 to its rightmost position as shown in FIG. 19 byvirtue of theprojections 101, 102 and 103 on the card 100.

It is also to be noted that the making and breaking of the contacts withthe present invention, as shown in FIGS. 18 and 19, exactly duplicatesthe making and breaking of contacts in the prior art conventional linelink switch described in the introduction to this specification.Furthermore, the configuration of the leaf springs and also of the cardl-can be exactly the same as the prior art. The important and inventivedifference is in the manner in which the leaf springs are connected intothe base 20 and the manner in which the leaf springs make electricalconnection with the lead-in wires 30 through 36 of FIG. 4.

In FIG. 20 there is shown a top view of the card 100.

It can be seen from FIG. 20 that the projections 101,

I02 and 103 are sufficiently wide to grip the two legs formed bybifurcating the ends of the leaf springs 26, 24 and 21 of FIGS. 18 and19.

The stamped out portion of leaf springs 27, 25, 23 and 22 between thebifurcated legs thereof is sufficiently wide so that the card 100 willpass therethrough from its leftmost position in FIG. 18 to its rightmostposition in FIG. 19, without engaging the bifurcated legs of said leafsprings 27, 25, 23 and 22. The projections 101,102 and 103 do not at anytime come into contact with the leaf springs 27, 25, 23 and 22. Only theleaf springs 26, 24 and 21 are activated by the projections 101, 102 and103. Of these three leaf springs 26, 24 and 21 only the leaf springs 26and 24 are activated to engage adjacent leaf springs 25 and 23respectively, as shown in FIGS. 18 and 19.

It is to be understood that the form of the invention shown herein isbut a preferred embodiment thereof and that various changes in specificdesign of the leaf springs of the housing base can be made withoutdeparting from the spirit or scope thereof. For example, while thedescribed embodiment of the invention is a line link switch used in thetelephone industry the principles of the invention are applicable toalmost any application involving a plurality of leaf springs held in acommon base and activated by a card means.

What is claimed is: I l. A leaf spring type switch comprising: aplurality of leaf spring contacts having a longitudi nal axis; aplurality of lead-in wires; a base of molded, insulative materialcomprising a plurality of slots formed therein and positioned in aside-by-side relationship with each other in a stacked manner, and withsaid slots all opening in substantially the same direction from saidbase; each slot lying in a separate plane with said separate planespositioned to intersect a first given plane at parallel lines ofintersection; said base further comprising a plurality of aperturesformed therein, each of said apertures being oriented to intersectdifferent ones of said slots;

one of said lead-in wires being inserted in each of said apertures tointersect said different ones of said slots;

one of said leaf spring contacts being retained in each of said slotswith its longitudinal axis being substantially perpendicular to saidparallel lines of intersection;

at least some of said leaf spring contacts having a 6 notch formedtherein, with said notch of each leaf spring contact being positioned toengageably slide over the particular lead-in wire inserted in theaperture which intersects with the slot in which said each leaf springcontact is inserted, to thereby make electrical contact with saidparticular lead-in wire; and actuating means for connecting anddisconnecting slective ones of said leaf spring contacts. 2. A leafspring type switch in accordance with claim 1 in which:

each of said leaf spring contacts comprises holding elements formedthereon which contact the sides of the slot in said base to securelyhold said leaf spring contact in the slot in which it is inserted; and

in which said notched appendage is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof.

3. A leaf spring type switch in accordance with claim 1 in which each ofsaid leaf spring contacts has its free end bifurcated with a cut-outportion of distinct configuration between the two legs formed by saidbifurcation, and further comprising: I

card means positioned within said cut-out portions of said leaf springscontacts and constructed to move selected ones of said leaf springscontacts to make and break electrical contact between predetermined onesof said leaf spring contacts. 4. A leaf spring type switch in'accordancewith claim 3 in which:

each of said leaf spring contacts comprises holding elements formedthereon which contact the sides of the slot in said base to securelyhold said leaf spring contact in the slot in which it is inserted; andin which said notched appendage is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof. 5;A leaf spring type switch comprising: a base of molded, insulativematerial comprising a plurality of slots formed therein and positionedin a side-by-side relationship with each other in a stacked manner andwith said slots all opening in substantially the same direction fromsaid base;

each slot lying in a separate plane parallel with the I planes of theother slots; v

said base further comprising a plurality of apertures, each of saidapertures being oriented to intersect different ones of said slots;

a plurality of insulated lead-in wires individually inserted in each ofsaid apertures to intersect said different ones of said slots;

a plurality of leaf springs each inserted in a given one of said slotsand each comprising an element thereon constructed to engage the lead-inwire intersecting said given slot to remove the insulation from saidintersecting lead-in wire and to make electrical connection therewith;and

actuating means for connecting and disconnecting selective ones of saidleaf springs.

6. A leaf spring type switch in accordance with claim 5 in which:

each of said leaf springs comprises holding elements formed thereonwhich contact the sides of the slot in said molded base to securely holdsaid leaf spring in the slot in which it is inserted; and

in which said element is constructed to mechanically grip saidintersecting lead-in to prevent unauthorized withdrawal thereof.

7. A leaf spring type switch in accordance with claim 5 in which each ofsaid leaf springs has the free end thereof bifurcated with a cut-outportion of distinct configuration between the two legs formed by saidbifurcation, and further comprising:

card means positioned within said cut-out portions of said leaf springsand constructed to move selected ones of said leaf springs to make andbreak electrical contact between predetermined ones of said leaf spring.8. A leaf spring type switch in accordance with claim 7 in which:

each of said leaf springs comprises holding elements formed thereonwhich contact the sides of the slot in said molded base to securely holdsaid leaf spring in the slot in which it is inserted; and

in which said element is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof.

9. A leaf spring switch comprising:

a base of insulative material and comprising:

a plurality of slots formed therein and positioned side-by-side in astacked manner in parallel planes;

a plurality of apertures formed therein, each oriented to intersect atleast one of said slots;

a plurality of insulated lead-in wires individually inserted in one eachof said apertures to thereby intersect at least one of said slots; and

a leaf spring inserted in each of said slots, and comprising an elementconstructed to engage the intersecting lead-in wire to remove theinsulation from said intersecting lead-in wire and to make electricalconnection therewith; and

actuating means to connect together selected ones of said leaf springs.

10. A leaf spring type switch in accordance with claim 9 in which:

each of said leaf springs comprises holding elements formed thereonwhich contact the sides of the slot in said base to securely hold saidleaf spring in the slot in which it is inserted; and

in which said element is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof.

11. A leaf spring type switch in accordance with claim 9 in which eachof said leaf springs has the free end thereof bifurcated with a cut-outportion of distinct configuration between the two legs formed by saidbifurcation, and further comprising:

card means positioned within said cut-out portions of said leaf springsand constructed to move selected ones of said leaf springs to make andbreak electrical contact between predetermined ones of said leaf spring.

12. A leaf spring type switch in accordance with claim 11 in which:

each of said leaf springs comprises holding elements formed thereonwhich contact the sides of the slot in said base to securely hold saidleaf spring in the slot in which it is inserted; and

in which said element is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof.

13. A switch assemblage in accordance with claim 9 in which:

each of said base portions comprises holding elements formed thereonwith contact the sides of the slot in said base to securely hold saidcontact in the slot in which it is inserted; and

in which said element is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof.

14. A switch assemblage in accordance with claim 9 in which each of saidcontacts has its free end therof bifurcated with a cut-out portion ofdistinct configuration between the two legs formed by said bifurcation,and further comprising:

card means positioned within said cut-out portions of said contacts andconstructed to move selected ones of said contacts to make and breakelectrical contact between predetermined ones of said contacts.

15. A leaf spring type switch assemblage in accordance with claim 14 inwhich:

each of said leaf springs comprises holding elements formed thereonwhich contact the sides of the slot in said base to securely hold saidleaf spring in the slot in which it is inserted; and

in which said element is constructed to mechanically grip saidintersecting lead-in wire to prevent unauthorized withdrawal thereof.

16. A switch assemblage comprising:

a plurality of contacts each comprising a flat base portion;

a plurality of lead-in wires;

a base of molded, insulation material having a plurality of parallelslots therein arranged in a stacked manner, and a plurality of aperturestherein each oriented to intersect at least one of said slots;

a lead-in wire inserted in each aperture to intersect a slot;

a base portion of a contact retained in each slot;

said slots and apertures being arranged and constructed to enable thebase portion of each contact to intersect one lead-in wire to theexclusion of the remaining lead-in wires; and

each base portion comprising an element constructed to engage theintersecting lead-in wire to make electrical contact therewith; and

means for making electrical contact between selected ones of saidcontacts.

1. A leaf spring type switch comprising: a plurality of leaf springcontacts having a longitudinal axis; a plurality of lead-in wires; abase of molded, insulative material comprising a plurality of slotsformed therein and positioned in a side-by-side relationship with eachother in a stacked manner, and with said slots all opening insubstantially the same direction from said base; each slot lying in aseparate plane with said separate planes positioned to intersect a firstgiven plane at parallel lines of intersection; said base furthercomprising a plurality of apertures formed therein, each of saidapertures being oriented to intersect different ones of said slots; oneof said lead-in wires being inserted in each of said apertures tointersect said different ones of said slots; one of said leaf springcontacts being retained in each of said slots with its longitudinal axisbeing substantially perpendicular to said parallel lines ofintersection; at least some of said leaf spring contacts having a notchformed therein, with said notch of each leaf spring contact beingpositioned to engageably slide over the particular lead-in wire insertedin the aperture which intersects with the slot in which said each leafspring contact is inserted, to thereby make electrical contact with saidparticular lead-in wire; and actuating means for connecting anddisconnecting slective ones of said leaf spring contacts.
 2. A leafspring type switch in accordance with claim 1 in which: each of saidleaf spring contacts comprises holding elements formed thereon whichcontact the sides of the slot in said base to securely hold said leafspring contact in the slot in which it is inserted; and in which saidnotched appendage is constructed to mechanically grip said intersectinglead-in wire to prevent unauthorized withdrawal thereof.
 3. A leafspring type switch in accordance with claim 1 in which each of said leafspring contacts has its free end bifurcated with a cut-out portion ofdistinct configuration between the two legs formed by said bifurcation,and further comprising: card means positioned within said cut-outportions of said leaf springs contacts and constructed to move selectedones of said leaf springs contacts to make and break electrical contactbetween predetermined ones of said leaf spring contacts.
 4. A leafspring type switch in accordance with claim 3 in which: each of saidleaf spring contacts comprises holding elements formed thereon whichcontact the sides of the slot in said base to securely hold said leafspring contact in the slot in which it is inserted; and in which saidnotched appendage is constructed to mechanically grip said intersectinglead-in wire to prevent unauthorized withdrawal thereof.
 5. A leafspring type switch comprising: a base of molded, insulative materialcomprising a plurality of slots formed therein and positioned in aside-by-side relationship with each other in a stacked manner and withsaid slots all opening in substantially the same direction from saidbase; each slot lying in a separate plane parallel with the planes ofthe other slots; said base further comprising a plurality of apertures,each of said apertures being oriented to intersect different ones ofsaid slots; a plurality of insulated lead-in wires individually insertedin each of said apertures to intersect said different ones of saidslots; a plurality of leaf springs each inserted in a given one of saidslots and each comprising an element thereon constructed to engage thelead-in wire intersecting said given slot to remove the insulation fromsaid intersecting lead-in wire and to make electrical connectIontherewith; and actuating means for connecting and disconnectingselective ones of said leaf springs.
 6. A leaf spring type switch inaccordance with claim 5 in which: each of said leaf springs comprisesholding elements formed thereon which contact the sides of the slot insaid molded base to securely hold said leaf spring in the slot in whichit is inserted; and in which said element is constructed to mechanicallygrip said intersecting lead-in to prevent unauthorized withdrawalthereof.
 7. A leaf spring type switch in accordance with claim 5 inwhich each of said leaf springs has the free end thereof bifurcated witha cut-out portion of distinct configuration between the two legs formedby said bifurcation, and further comprising: card means positionedwithin said cut-out portions of said leaf springs and constructed tomove selected ones of said leaf springs to make and break electricalcontact between predetermined ones of said leaf spring.
 8. A leaf springtype switch in accordance with claim 7 in which: each of said leafsprings comprises holding elements formed thereon which contact thesides of the slot in said molded base to securely hold said leaf springin the slot in which it is inserted; and in which said element isconstructed to mechanically grip said intersecting lead-in wire toprevent unauthorized withdrawal thereof.
 9. A leaf spring switchcomprising: a base of insulative material and comprising: a plurality ofslots formed therein and positioned side-by-side in a stacked manner inparallel planes; a plurality of apertures formed therein, each orientedto intersect at least one of said slots; a plurality of insulatedlead-in wires individually inserted in one each of said apertures tothereby intersect at least one of said slots; and a leaf spring insertedin each of said slots, and comprising an element constructed to engagethe intersecting lead-in wire to remove the insulation from saidintersecting lead-in wire and to make electrical connection therewith;and actuating means to connect together selected ones of said leafsprings.
 10. A leaf spring type switch in accordance with claim 9 inwhich: each of said leaf springs comprises holding elements formedthereon which contact the sides of the slot in said base to securelyhold said leaf spring in the slot in which it is inserted; and in whichsaid element is constructed to mechanically grip said intersectinglead-in wire to prevent unauthorized withdrawal thereof.
 11. A leafspring type switch in accordance with claim 9 in which each of said leafsprings has the free end thereof bifurcated with a cut-out portion ofdistinct configuration between the two legs formed by said bifurcation,and further comprising: card means positioned within said cut-outportions of said leaf springs and constructed to move selected ones ofsaid leaf springs to make and break electrical contact betweenpredetermined ones of said leaf spring.
 12. A leaf spring type switch inaccordance with claim 11 in which: each of said leaf springs comprisesholding elements formed thereon which contact the sides of the slot insaid base to securely hold said leaf spring in the slot in which it isinserted; and in which said element is constructed to mechanically gripsaid intersecting lead-in wire to prevent unauthorized withdrawalthereof.
 13. A switch assemblage in accordance with claim 9 in which:each of said base portions comprises holding elements formed thereonwith contact the sides of the slot in said base to securely hold saidcontact in the slot in which it is inserted; and in which said elementis constructed to mechanically grip said intersecting lead-in wire toprevent unauthorized withdrawal thereof.
 14. A switch assemblage inaccordance with claim 9 in which each of said contacts has its free endtherof bifurcated with a cut-out portion of distinct configurationbetween the two legs Formed by said bifurcation, and further comprising:card means positioned within said cut-out portions of said contacts andconstructed to move selected ones of said contacts to make and breakelectrical contact between predetermined ones of said contacts.
 15. Aleaf spring type switch assemblage in accordance with claim 14 in which:each of said leaf springs comprises holding elements formed thereonwhich contact the sides of the slot in said base to securely hold saidleaf spring in the slot in which it is inserted; and in which saidelement is constructed to mechanically grip said intersecting lead-inwire to prevent unauthorized withdrawal thereof.
 16. A switch assemblagecomprising: a plurality of contacts each comprising a flat base portion;a plurality of lead-in wires; a base of molded, insulation materialhaving a plurality of parallel slots therein arranged in a stackedmanner, and a plurality of apertures therein each oriented to intersectat least one of said slots; a lead-in wire inserted in each aperture tointersect a slot; a base portion of a contact retained in each slot;said slots and apertures being arranged and constructed to enable thebase portion of each contact to intersect one lead-in wire to theexclusion of the remaining lead-in wires; and each base portioncomprising an element constructed to engage the intersecting lead-inwire to make electrical contact therewith; and means for makingelectrical contact between selected ones of said contacts.